A concept of an MA is defined in 802.1 ag, and the MA includes an important parameter, that is, an MA virtual local area network (VLAN). The MA corresponds to at least two maintenance association end points (MEP), an optical line terminal (OLT) respectively configures the at least two MEPs on at least two optical network units (ONU) that are connected to the OLT, so that each of the at least two devices can use the MA as a local MA. However, in an actual application scenario, different ONUs generally have different VLANs, and VLAN translation may occur on a single ONU, a single OLT, or both an ONU and an OLT. Therefore, MA VLANs of different ONUs are different, and multiple ONUs cannot use a same MA as a local MA. If the multiple ONUs use a same MA as a local MA, the OLT needs to configure multiple MAs, and then respectively send the MAs to ONUs corresponding to the MAs, causing a great amount of configuration.